The Backstory
Wiring
Blynk Setup
The Mechanical Stuff + 3D Modeling
The Base Prototype
The Final Product (Will Return soon when the ideal components are 3D printed

Published May 3, 2021 © GPL3+

Remote Control Robotic Mic Stand

Control the position of a microphone stand remotely through Blynk.

IntermediateWork in progress8 hours611

Things used in this project

Hardware components

SG90 Micro-servo motor

TowerPro MG995R High Torque Servo

Jumper wires (generic)

Particle Argon

Breadboard (generic)

Software apps and online services

Blynk

Particle Build Web IDE

Onshape

**Optional if you want to modify any of the 3D modeled files.

Hand tools and fabrication machines

Multitool, Screwdriver

To fix the fins on the servo if you are working with crafts. The torque produced by the weight of the crafts can cause the fins to fall off if they aren't fixed with the given screw.

3D Printer (generic)

**Optional for 3D printing components, STP files will be handed.

Story

Are you a wannabe gamer streamer? Do you like recording music and podcasts? Do you have a microphone that you can't leave still without occupying one hand? Then this product must be for you!

The Backstory

Having my PC for five years now, a major concern of mine is communication and sound recording for a different class I have involving the recording of music, podcasts, etc. While searching for old electronics in the household, I found a small, high quality microphone my dad had that was really sweet.

However, my only caveat was that the given microphone didn't have a stand, so if I was in a call or had to record anything, I had to use up a whole hand to do so. This was extremely frustrating as I had to constantly pick up the microphone to speak. Unfortunately, since I am not a Hindu deity, I only have two hands, which makes recording any musical instrument impossible, especially for my sound engineering class which required that.

Nonetheless, I persisted with the idea of having a microphone stand that can adjust positions at ease with a simple user interface, so that I can fit any instrument or any object in the studio and fix the microphone in place. Let's dive into it.

Wiring

This was actually the first portion that I tried getting down as it determined whether or not my equipment would actually work for the job before I consider investing more for the mechanical components.

My initial plan started out with a wiring diagram that involved me connecting both the MG995R and the SG90 to be connected to the positive power rail and ground power rails, which were connected to the Argon's 5 Volt VUSB pin and ground pins respectively. However, when setting up the servos, there was a major problem that was encountered as that specific wiring setup did not provide a consistent 5 volt induced current to power the MG995R for more than 10 seconds after startup before it jammed.

I originally believed it was a faulty servo, and later on tested a similar wiring setup with a stepper motor, the motor occasionally jammed as well. When I swapped the servo out for another one, the other one jammed. I swapped out Argons, etc. and still encountered the same error, but not for the SG90 which was able to function off of a lower current. It was then when I encountered the solution which was that the SG90 and the MG995R cannot be powered by the same VUSB pin or on a power rail without it jamming. Therefore, I instead changed the SG90 to gain current from the 3V3 pin of the Argon, which worked well for both servos.

Additionally, supplying the argon with a current from my PC's USB ports caused occasional jamming as well, so instead I used a wall wart to provide a 5 volt induced current. Any wall charger for android smartphone device also works.

Blynk Setup

The next portion was more straightforward as it involved pushing data from my smartphone to the Argon, which is an MCU that can receive data from Particle's cloud via Wi-Fi. This part just needed me to set up a UI with a virtual pin that can be pushed to Particle's cloud and written as an integer that can be used to write the position of the Servo motor. This method was done by pushing data through a virtual pin and taking the parameters in the Argon's firmware to write to the signal to the Servo motor.

1 / 3

The Mechanical Stuff + 3D Modeling

I have officially decided I am not going to become a mechanical engineer anytime soon. If anyone that is more experienced wants to make their take, go ahead.

My initial drawings for 3D modeling was drafted on the idea that I could attach the model to the end of my desk in a C-Clamp design and have the MG995R control the horizontal rotation axis as the SG90 controls the vertical rotation axis. The dimensions and the pitches that I had to make to develop custom screws, etc. had to be altered over time.

1 / 2 • Updated Design Plan

The 3D modeling part on OnShape was especially difficult as I had to completely self teach myself each of the components. However, my final design of the 3D components still held a similar design plan that I am proud of as they appear to fit well with the dimensions of each part of my project.

1 / 3 • The base C-Clamp design (Fixed on the end of the desk)

This portion was painstakingly difficult. However, if I were to finalize this design, I would change the assigned servos of each component so that the MG995R would control the vertical axis of rotation that holds the SG90, which controls the horizontal axis of rotation.

It was then when I realized I had one big problem: Finding a printer that could actually print this.

The Base Prototype

Figuring out that I wouldn't be able to print this out on time, I decided instead to get a few craft supplies from Michaels and put together a rough prototype of this design using wood.

My initial problem was that I had to use counterweights to hold each part of the project together as it was loosely fixed on the desk (I can't drill holes on my desk). I went through drawing and figuring out the displacement between each component on each axis using a Free Body Diagram (FBD) in labeling all of the possible forces.

My first (FBD) worked but was inefficient as the servos were so far apart I had to use multiple jumper cables to have them reach the Argon and they could only rotate so far. The other problem is the longer the connection means the greater the resistance, which could result in performance issues and stuttering for both of the Servos as they are not supplied a stable current.

My second FBD worked more efficiently as the displacement between both components was minimal as the vertical axis of rotation was placed on the middle. To compensate, however, I had to use counterweights. The major problem with counterweights was that they increased the rotational inertia of each rod used, which provided a challenge for the SG90 micro servo as greater rotational inertia means greater countertorque by gravity, so I swapped the positions of the SG90 and the MG995R to find the project working more efficiently.

The only problem that remained was that I could not accelerate the servos that quickly, or else the rods would stay at the same velocity and cause the whole project to fall apart.

Anyways, this was the final product of my rough prototype.

1 / 2 • Servos, counterweights, etc.

The Final Product (Will Return soon when the ideal components are 3D printed)

Schematics

Code

servoblynkcontrols.ino

/* 
*    Copyright (C) Gabriel Inojosa 2021
*
*    This program is free software: you can redistribute it and/or modify
*    it under the terms of the GNU General Public License as published by
*    the Free Software Foundation, either version 3 of the License, or
*    (at your option) any later version.
*
*    This program is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*    GNU General Public License for more details.
*
*    You should have received a copy of the GNU General Public License
*    along with this program.  If not, see <https://www.gnu.org/licenses></https:>.
*/

// This #include statement was automatically added by the Particle IDE.
#include <blynk.h>


// Authorization code is sent from Blynk to your email
// after creating a new project in the app.
char auth[] = " "; //INSERT AUTHENTICATION KEY FROM BLYNK HERE

Servo horizontalServo;
Servo vertServo;

void setup()
{
    pinMode(D3, OUTPUT);
    Blynk.begin(auth);  // Connects Argon to Blynk Cloud
    
    horizontalServo.attach(6);
    horizontalServo.write(10); // I always choose a starting pos for my servo
    
    vertServo.attach(2);
    vertServo.write(10);
    delay(25);
    
}

BLYNK_WRITE(V0)
{
    horizontalServo.write( param.asInt() );
}

BLYNK_WRITE(V1)
{
    vertServo.write( 170 - param.asInt() );
}

void loop()
{
    digitalWrite(D3, HIGH);
    Blynk.run();
}

Remote Control Robotic Mic Stand

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

The Backstory

Wiring

Blynk Setup

The Mechanical Stuff + 3D Modeling

The Base Prototype

The Final Product (Will Return soon when the ideal components are 3D printed)

Custom parts and enclosures

C Clamp STL File

Horizontal Rotation Servo Bar

Custom SG90 Servo Hub

Schematics

Wiring Setup

Code

servoblynkcontrols.ino

Credits

Gabriel Inojosa

Comments

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Remote Control Robotic Mic Stand

Remote Control Robotic Mic Stand

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

The Backstory

Wiring

Blynk Setup

The Mechanical Stuff + 3D Modeling

The Base Prototype

The Final Product (Will Return soon when the ideal components are 3D printed)

Custom parts and enclosures

C Clamp STL File

Horizontal Rotation Servo Bar

Custom SG90 Servo Hub

Schematics

Wiring Setup

Code

servoblynkcontrols.ino

Credits

Gabriel Inojosa

Comments

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